diff --git a/README.md b/README.md
index 10f008b..f142cf9 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ We plan to support more chains in the future. If you would like to use Holonym o
     ```JSON
     {
         "hasValidSbt": false,
-        "message": "SBT is expired or does not exist" 
+        "message": "SBT is expired or does not exist"
     }
     ```
 
@@ -76,7 +76,7 @@ See the following documentation [How to get user's proofs](https://holonym.gitbo
   | name              | description                       | type   | in    | required |
   | ----------------- | --------------------------------- | ------ | ----- | -------- |
   | `credential-type` | 'gov-id', 'epassport', or 'phone' | string | path  | true     |
-  | `network`         | 'optimism' or 'optimism-goerli'   | string | path  | true     |
+  | `network`         | 'optimism' or 'base-sepolia'      | string | path  | true     |
   | `user`            | User's blockchain address         | string | query | true     |
   | `action-id`       | Action ID                         | string | query | true     |
 
diff --git a/src/constants/HubV3TestnetABI.js b/src/constants/HubV3TestnetABI.js
new file mode 100644
index 0000000..7b21462
--- /dev/null
+++ b/src/constants/HubV3TestnetABI.js
@@ -0,0 +1,20 @@
+export default [
+  "function balanceOf(address) view returns (uint256)",
+  "function getApproved(uint256) view returns (address)",
+  "function getIdentifier(address,bytes32) pure returns (bytes32)",
+  "function getSBT(address,bytes32) view returns (tuple(uint256,uint256[],bool))",
+  "function isApprovedForAll(address,address) view returns (bool)",
+  "function name() view returns (string)",
+  "function owner() view returns (address)",
+  "function ownerOf(uint256) view returns (address)",
+  "function renounceOwnership()",
+  "function revokeSBT(address,bytes32)",
+  "function sbtOwners(bytes32) view returns (uint256, bool)",
+  "function setSBT(bytes32 circuitId, address sbtReceiver, uint expiration, uint nullifier, uint[] calldata publicValues)",
+  "function supportsInterface(bytes4) view returns (bool)",
+  "function symbol() view returns (string)",
+  "function tokenURI(uint256) view returns (string)",
+  "function transferOwnership(address)",
+  "function usedNullifiers(uint256) view returns (bool)",
+  "function getSBTByNullifier(uint256 nullifier) view returns (tuple(uint256 expiry, uint256[] publicValues, bool revoked) sbt)",
+];
diff --git a/src/constants/misc.js b/src/constants/misc.js
index b345d36..53e785b 100644
--- a/src/constants/misc.js
+++ b/src/constants/misc.js
@@ -3,6 +3,9 @@ export const defaultActionId = 123456789;
 export const hubV3Address = "0x2AA822e264F8cc31A2b9C22f39e5551241e94DfB";
 export const hubV3Chain = 10;
 
+export const hubV3TestnetAddress = "0x98221c937C51f5bBe615CB104435395c93b1AD8D";
+export const hubV3TestnetChain = 84532;
+
 export const govIdIssuerAddress =
   "0x03fae82f38bf01d9799d57fdda64fad4ac44e4c2c2f16c5bf8e1873d0a3e1993";
 export const phoneIssuerAddress =
@@ -18,10 +21,10 @@ export const v3PhoneSybilResistanceCircuitId =
   "0xbce052cf723dca06a21bd3cf838bc518931730fb3db7859fc9cc86f0d5483495";
 export const v3EPassportSybilResistanceCircuitId =
   "0xf2ce248b529343e105f7b3c16459da619281c5f81cf716d28f7df9f87667364d";
-export const v3CleanHandsCircuitId = 
+export const v3CleanHandsCircuitId =
   "0x1c98fc4f7f1ad3805aefa81ad25fa466f8342292accf69566b43691d12742a19";
 
-export const ePassportIssuerMerkleRoot = 
+export const ePassportIssuerMerkleRoot =
   "0x111abc2c2de1738067395fa944c07ce6e44c4a38accfed392797bb94cee2cdac";
 
 export const zeronymCleanHandsEthSignSchemaId = "onchain_evm_10_0x8";
diff --git a/src/services/sybil-resistance.js b/src/services/sybil-resistance.js
index 3b9e6ae..3429c92 100644
--- a/src/services/sybil-resistance.js
+++ b/src/services/sybil-resistance.js
@@ -10,6 +10,7 @@ import {
 } from "../constants/contractAddresses.js";
 import {
   hubV3Address,
+  hubV3TestnetAddress,
   govIdIssuerAddress,
   phoneIssuerAddress,
   v3KYCSybilResistanceCircuitId,
@@ -19,6 +20,67 @@ import {
 } from "../constants/misc.js";
 import AntiSybilStoreABI from "../constants/AntiSybilStoreABI.js";
 import HubV3ABI from "../constants/HubV3ABI.js";
+import HubV3TestnetABI from "../constants/HubV3TestnetABI.js";
+
+// ---------------------------------------------
+// Testnet stuff
+// ---------------------------------------------
+
+async function sybilResistanceKycTestnet(req, res) {
+  const address = req.query.user;
+  const actionId = req.query["action-id"];
+  if (!address) {
+    return res
+      .status(400)
+      .json({ error: "Request query params do not include user address" });
+  }
+  if (!actionId) {
+    return res
+      .status(400)
+      .json({ error: "Request query params do not include action-id" });
+  }
+  if (!assertValidAddress(address)) {
+    return res.status(400).json({ error: "Invalid user address" });
+  }
+  if (!parseInt(actionId)) {
+    return res.status(400).json({ error: "Invalid action-id" });
+  }
+
+  // Check blocklist first
+  // const blockListResult = await blocklistGetAddress(address);
+  // if (blockListResult.Item) {
+  //   return res.status(200).json({ result: false });
+  // }
+
+  // const network = req.params.network;
+
+  const provider = providers["base-sepolia"];
+
+  const hubV3Contract = new ethers.Contract(
+    hubV3TestnetAddress,
+    HubV3TestnetABI,
+    provider
+  );
+
+  // Check v3 contract for KYC SBT
+  try {
+    const sbt = await hubV3Contract.getSBT(address, v3KYCSybilResistanceCircuitId);
+
+    // For sandbox, we don't care about expiry or issuer or action ID. We just
+    // check whether the user has an SBT.
+
+    return res.status(200).json({ result: !!sbt });
+  } catch (err) {
+    if ((err.errorArgs?.[0] ?? "").includes("SBT is expired")) {
+      return res.status(200).json({ result: false });
+    }
+
+    throw err;
+  }
+}
+// ---------------------------------------------
+// END: Testnet stuff
+// ---------------------------------------------
 
 async function sybilResistanceGovIdNear(req, res) {
   const user = req.query.user;
@@ -123,6 +185,8 @@ async function sybilResistanceGovId(req, res) {
   try {
     if (req.params.network === "near") {
       return await sybilResistanceGovIdNear(req, res);
+    } else if (req.params.network === "base-sepolia") {
+      return await sybilResistanceKycTestnet(req, res);
     }
 
     const address = req.query.user;
diff --git a/src/services/testnet-minter.js b/src/services/testnet-minter.js
index 6bcfa59..728bb40 100644
--- a/src/services/testnet-minter.js
+++ b/src/services/testnet-minter.js
@@ -1,6 +1,10 @@
 import { randomBytes } from "crypto";
 import { ethers } from "ethers";
-import { v3KYCSybilResistanceCircuitId } from "../constants/misc.js";
+import {
+  hubV3TestnetAddress,
+  v3KYCSybilResistanceCircuitId,
+} from "../constants/misc.js";
+import HubV3TestnetABI from "../constants/HubV3TestnetABI.js";
 import { providers } from "../init.js";
 
 export async function setKycSbt(req, res) {
@@ -12,11 +16,11 @@ export async function setKycSbt(req, res) {
 
     const { circuitId, sbtReceiver, expiration, nullifier, publicValues } = req.body;
 
-    const abi = [
-      "function setSBT(bytes32 circuitId, address sbtReceiver, uint expiration, uint nullifier, uint[] calldata publicValues)",
-    ];
-    const address = "0x98221c937C51f5bBe615CB104435395c93b1AD8D";
-    const contract = new ethers.Contract(address, abi, testnetMinterWallet);
+    const contract = new ethers.Contract(
+      hubV3TestnetAddress,
+      HubV3TestnetABI,
+      testnetMinterWallet
+    );
 
     const tx = await contract.setSBT(
       // circuitId,